| Pigment from flowers of Leucosceptrum Canum (Smith) is a natural yellow pigment at very high content. Our Previous studies indicated that this pigment was stable when exposed to light, heat, acids, oxidizers or reducing agents. It is water soluble and showed antioxidant activity. And the toxicological studies indicated it was nontoxic. Accordingly, this pigment is very promising in the development of natural yellow pigment. In this study, the optimal conditions for extraction and purification of this pigment, and its application in fried instant noodles were investigated.Effects of different temperatures and concentrations of ethanol on the pigment extraction yield, the content of solids, reducing sugars and polysaccharide were studied. The purification efficiency of pigment was determined by the methods of ethanol precipitation and activated charcoal adsorption, and application of the pigment in instant noodle was also investigated. Experimental results showed that pigment yield extracted by ethanol aqueous solution was higher than than that by pure water. Increase in extraction temperature and the concentration of ethanol could increase pigment yield from the flower of L. canum. The optimal extraction conditions were as follows: one part of dried flower was extracted with 10 volume of 50%-60% of ethanol by twice, stirred at 60℃for 30 min. The pigment purification experiments showed that ethanol could precipitate part of polysaccharides in the extracts and the efficiency increased with the concentration of ethanol increased. Activated charcoal showed strong adsorption for the pigment from L. canum, and 95% of reducing sugars and 92% of the polysaccharides could be removed by rinsing in boiling. However, no tested eluents were found to effectively elute the pigment from activated charcoal. Extraction experiments showed that 96% of the pigment from L. canum was recovered from the fried noodles, which indicated its high stability of this pigment during frying.
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